Ask for authorization to Photo Roll without writing to it

Question

I am using ALAssetLibrary and would like iOS to automatically show the permission dialog to the user when the authorization status is not determined without adding anything new to the Photo Roll itself.

Currently I am using on the AppDelegate :

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // checks for permission, iOS automatically prompt the first boot if not
    ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];

    if (status == ALAuthorizationStatusNotDetermined) {
        [AssetsLibraryWrapper sharedInstance] createGroupAlbum];
    }    

    return YES;
}

This unfortunately creates a new Album in the library that I would like to avoid.

Answer 1

Instead of creating a group, use ALAssetsLibrary and simply try to enumerate the groups.

if (status == ALAuthorizationStatusNotDetermined) {
    ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
    [lib enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
        // Access granted
        *stop = YES; // no need to complete iteration
    } failureBlock:^(NSError *error) {
        // Access denied
    }
}